Unsaturated bicyclic glycols



Patented Mar. 11, 1947 um'rsos'rarss rATtENr OFFICE i.

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nicrcnrc GLYCOLS ,"iym, and Warren punt-aer- Iscraon, Philadelphia, Pa,

Products at Chemi- Gornpany, Pa, a co p ration swam. 7 llcation'-o.xois. s zmt. scars a 1 This invention wherein R is hydrdg ,or amethyl group.

Typical alkaline condensing agents for the purpose are the hydroxides ofthe alkali metals and of the alkaline earth metals, such as sodiumhydroxide, potassium hydroxide, calcium hydroxide, strontium hydroxide.or barium hydroxide, or carbonates of the alkali metals, notably sodiumcarbonate and potassium carbonate. Quaternary ammonium hydroxides. suchas benzyi trimethyl ammonium hydroxide or dibenzyl dlmethyl ammoniumhydroxide, can also be used.

Formaldehyde may be used in the form of an aqueous solution, the tosolutions of commerce being particularly suitable, or may be suppliedfrom a polymer such as parai'ormaldehyde.

The reaction is conveniently eflected in aqueous or solvent solution attemperatures from about 20 up to 80 C. Since the reaction is exothermic,it is desirable to control the reaction with external cooling or by slowmixing. The alkaline catalyst is then destroyed and the glycolseparated. The products may be purified by recrystallization withseparation of ma and trans-isomers.

The following examples ilustrate the invention:

Example 1 To a rapidLy stirred mixture of 61 grams of ,5endoznethylene-A tetrahydrobenzaldehyde, 200 cc. of water, and 30 gramsof r-maide- 2 Hide. trierwas ad eu 50 mm: of calciumi tim s amp r a m sethe uddltioot temperature rose mduany ta 50 .0. ,Stlrfins'was continuedfor-one and one hair li longer, and the mixture was-allowed to stanfor'eighteen hours at room temperature. The solid material was filteredoil by suctionand mixed on dilute hydrochloric aci'dto' -diss'olve partor the solids. The remaining solid material was washed with cold water,dried,- and distilled in vacuo."

The product distilled at 142-155 C. (2-3 mm.) and solidified to acolorless, wan, crystalline solid having the formula:

on C(l on,

H: CHrOH Upon recrystallization from a benzene-petroleum ether mixture,it formed white needles melting at HIP-114' C.

Example 2 To a stirred solution of 96 grams of 50% aqueous sodiumhydroxide cooled to 10 (2.. there was added a solution of 122 grams of2,5-endomethylene-A-tetrahydrcbenzaldehyde, 194 grams of- 37% aqueousformaldehyde, and 104 grams of ethanol during the course of one hourwhile the reaction temperature was maintained at 2045 C. with cooling.The mixture was then stirred and heated at 50-60 C. for two and one-hallhours. After being cooled to room temperature, the mixture was acidifiedwith dilute hydrochloric acid.

The glycol crystallized on cooling in an ice bath and was filtered oil.The ethanol was distilled off from the filtrate, and the residue wascooled in an ice bath. I The solid which separated from the residue wasfiltered oil and added to the glycol obtained above. The yield of crudeproduct thus obtained was 88 grams. It melted at 10'T-ll0' C. Afterrecrystallization from benzene-petroleum ether, the pure product meltedat 113"-l14' C. a in Example 1.

Example 3 To a stirred solution of 96 grams of aqueous 50% sodiumhydroxide which was cooled to 10 6.. there was added a solution of 136grams 0! 2,5- endomethylene-6-methyl-A -tetrahydrobenzaldehyde, 194 gramof 37% aqueous formaldehyde, and 370 grams of ethanol. The temperaturewas 3 maintained at air-30' 0. during the addition,

0 (Kl L i Oil-OH distilled at i85'-155' C. (1-4! mm.) and'crystallizedfrom petroleum ether. The crystals obtained melted at 69'-'l1 C. The!were dissolved in warm nitromethane. The crystals obtained therefrommelted at HIP-116' C. A second recrystallization from nitromethane savecrystals melting at 121 C. and, upon repeated crystallization, thecrystals obtained continued to melt at this temperature. This behavioris due to a cop ration of the less soluble isomer of the cyclic glycol.

The unsaturated aldehyde: uaed in the above examples are obtainable byheating cyclopentadiene with acrolein or crotonaldehyde as described byDieis and Alder. Annalen der Chemie, 460, 119 (1928).

m onion 4 We claim: 1. As a new compound. an unsaturated bicyclio glycolhaving the iormuia:

on 5 c l ca-n I K m omen wherein R is selected from a member oi theclass 01 hydrogen and the methyl group.

2. As a new compound. the unsaturated bicyclic xlycol; having theiormula:

CHiOH 3. As a new compound, the unsaturated bicyclie glycol having theformula:

Hi CEIOH HERMAN A. BRUBON. WARREN D. NIEDERHAUSER. HYMAN IBERSON.

